Engine starter



, June 17, 1947.

vG. s. THOMPSON `ENG1NE STARTER Filed May 4,' 1945 BEL , v if @A122275Umm/75ml Patented June 17, 1947 UNITED STATES RTENT. OFFICE i -nNcmESTARTER Glenn S. Thompson, Milwaukee, Wis., assigner to Briggs &Stratton Corporation, Milwaukee, Wis., a corporation of DelawareApplication May 4, 1945, Serial No. 591,921

tation therewith through a yieldable coupling embodying both torsionaland endwise resiliency for cushioning rearward end thrust of the pinionduring operation of the starter. Such a driving connection between theactuator and the power shaft'has resulted in complicated structures inthe past, and it is one of the objects of the present invention toprovide a simple manner of effecting a splined driving connectionbetween the actuator and a part fixed with respect to the power shaftwhich facilitates incorporation of endwise and torsional resiliency insaid driving connection.

More specifically, it is one of the objects of this invention to providean engine starter of the character described with a screw threadedactuator for the pinion having a sleeve extending axially therefrom andprovided with a longitudinal slot to receive a driving abutment on thepower shaft of the starter so that the actuator is splined' thereto, andwherein the yieldable coupling is mounted on said sleeve between saiddriving abutment and a partvof the actuator.

Another object of this invention resides in the provision of a noveldriving connection between the pinion actuator and the power shaft whichfacilitates limiting axial motion of the actuator relative to the powershaft.l

With the above and other objects in View which will appear as thedescription proceeds, this invention resides in the novel construction,combination, and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawing illustrates two complete examples of thephysical embodiment of the invention constructed according to the bestmodes so far devised for the practical application of the principlesthereof, and in which:

Figure 1 is a side elevational view of the starter of this inventionhaving parts thereof broken away and shown in section to betterillustrate details of construction with the pinion shown in itsinoperative retracted position;

11 Claims'. (Cl. I4-7) Figure 2 is a View similar to Figure 1 showingthe parts in the positions they occupy with the pinion in its operativeprojected engine cranking position;

Figure 3 is a fragmentary perspective view of a portion of the starterillustrating the manner in which the driving connection is establishedbetween the pinion actuator and the power shaft; and

Figure 4 is a fragmentary perspective View of a portion of a slightlymodified pinion actuator illustrating another manner of limiting axialVmotion of the actuator relative to the power shaft.

Referring now more particularly to the accompanying drawing in whichlike numerals indicate like parts, the numeral 5 generally designatesthe starter of this invention and which includes a tube ,6 telescopedover the power shaft 'l of the starting motor 8. The tube 6 unitarilymounts all of the starter parts and is adapted to be anchored to thepower shaft 'l of the starting motor, in a manner to be later described,so as toform in effect a part of the power shaft.

The customary drive pinion 9 is freely rotatable and slidable along theinner end portion of the tube 6 from an inoperative retracted position,shown in Figure 1, to an operative projected engine cranking position,shown in Figure 2, in which it meshes with an engine gear l0. 'I'heoperative cranking position of the pinion is dened by the customarypinion stop collar Il on the inner extremity of the tube adjacent to thestarting motor.

The pinion is provided with an externally screw threaded sleeve l2projecting axially from the pinion toward the outer end of the powershaft and which cooperates with an externally threaded pinion actuatorI3 in the customary manner to produce propulsion of the pinion to andfrom mesh with the engine gear upon rotation of the actuator relativeto` theA pinion and to drivingly connect the pinion to the actuator forrotation therewith through the interengaging screw threads of said partsupon interference with propulsion of the pinion toward mesh with theengine gear.

The manner in which the screw threaded pinion actuator is drivinglyconnected to the power shaft constitutes one of the features of thisinvention and for this purpose the actuator is provided with a sleeve I4encircling the power shaft and extending axially therealong in adirection away from the pinion 9 land toward the outer free end ofthepower shaft. Near the outer eX- tremity of the sleevey I4circumferentially spaced' The collar I6 also serves to anchor thetube5g,

to the power shaft so that the tube forms a part thereof. For thispurpose a s'et screw I8 -ispr'm vided having a shank threaded intoalignfdfhl's in the collar and sleeve with a, reduced end portion I9entering a suitable Wellin the siderof the, shaft to lock the collar andtube to the power shaft.

The forward end of the collar forms substantially a. cylindrical skirt2il' which telescopes rover the bifurcated endv of the. sleeveV Ifadistance such that the drive slots thereof are enclosed The forward edgeof the 'skirt Zil by the skirt. alsoforms an annular abutment which'cooperates withY abutrneiits 2li. formed by. theien'ds of the threads'on the. actuator 'adjacent t'o` the collar to 'denne an axial space fora bank 'of cupped spring washers 22 encircling the sleeve.

Iii-:and Y'confined between *said` abutments on the actuator andy skirt.28.

These 'spring washers tend to expandiandiurge the 'actuator axially awayfrom the collar I6 and4 inwardly alon'gthe power shaft. Such forwardaxial motion oi the actuator islimited; however, bylugs 23fstruckoutwardly from the extremities of-'t'nefdrive fingers duringassembly'o'f the parts into the slots 'I5u and engaging ove-r the outerend-oi the collar I6;

TheY spring washers 22 serv-e as cushioning meansytofyi'eldingly-absorbinotion of the vactua-- tor toward 'the collarsuchfais occurs as th'e result of end .thrust 'translated to rtheactuator 'from the pinionv during 'cranking `of the enginefa'sillustratedin'llligure 2. Thus, it will befseenthat the washersinyielding axially'providea deg're of torsional resiliency in lthedriving connection be tween the power shaft and pinion toeffectivelyprotect 'the starter against shock;

Because of 'the fact thati the Lendsofthe threads onthe actuator I3adjacent toithe collar I6 provide `one 'of the abutments against which-the that the vinner peripheral portion of the "spring washers areprevented from entering tliespaced slots I5 in the end of 'the sleeve.thestarter parts is thus precluded.

In the modification illustratediin Figurel, axial motionof the pinionactuator inwardly along the tubefaway from the `collar is vlirnited byanovel stop f'for'rned by a "detachable spring- 'ringl 25; snapped over4the bifurcated eXtrenilI-)yy of the sleeve. I4 .and sprung into-notches326 cutinto the side. edges `of the `-drivengers l I5. fadjaoei'it'itoJamming 'of their outer extremity. Hence, the spring ring 25 is broughtto bear against the outer face of the collar in the same manner as thelugs 23, but the detachability thereof enables ready disassembly of thestarter parts for inspection or replacement as required.

From the foregoing description taken in connection with the accompanyingdrawing., it will be readily apparent to those skilled in the art thatthe novel driving connection between the power shaft and pinion actuatorlies wholly to oneside of the cushioning means by which endwise andtorsional resiliency is achieved and that by reason of this factcompactness and simplicity of construction is assured.

What I claim as my invention is:

1. 'In an engin-e starter of the type having a pinionpropelled along apower shaft into and out oflmesh with an engine gear by relativerotation between screw threaded parts on the pinion and an actuator forther/pinion 'sli'dabl'y mounted on thepow'er shaft, 4afclrivi'n'geonnetion between the power 'shaft and actuatorfcmprisin'g: alcol-e. larfixed 0nthe powershaft andinavin'g y ilere'ntially spacedv longitudinalgroovesfin- 'it-sbore; drive ngers projecting axiallyfrom 'the actuator'and reeiv'edwithin `sa-i'dw-'g'ro'o'ires in the bore ofthe collartoprovide 'a lsplfined; driving connectionv 'between the i actuator andlthe collar per'rnittinfg*` a degree 'of *ajxiahmovenient-of the actuatortowa-rdfthe 'collaifin response to-errd thrust ldeveloped asthe starterpicks up theloa'd or 'ti-ie. engine, andy resilient cushioning-meansencircling --th-e actuator Wfh'ollyto 'one side 'ofjsali'dsplinedf'clr-iving con'ne'ction and reacting between. the actuator-andf'collar t'o yieldingly resist "s'a'ifdj` thrustof the actuator`during'operation ofjtne starter.

2. In an yengine l starter ofthe type 'hjaying au* pinion propelledalong a power shaft 'into and; out of mesh with an engine gear, by,relativer@- tatifon between screw threadediparts Amrftl'i'e pin: ion`and a-n actuator for the fpini'on VVsli ly Ino'iinted"v on lthe p ovve'rishaftpfa ldriving.'connection between` the powerv shaftanda'ctuagtorjcoj inprising: a collar iixed'on the power shaft andhaving -circum-fe'rentially spacedI lon'itud' all. grooves-in itsbore;`drive 'iingersprojecti'ng jaxiajlllyv-f-rorn-.the actuator and receivedwithnsaid; groovesv in the 'bore 'of the 'Collar t0. Til". fefa. splineddriving `connec'cion,between "the 'actuator and the `collarpermittin'gja Adegree offaxiailirnoyef ment off the actuator Ltoward thevcollar ref. spense to *end 'thrust' developedfas" :the starter. p'ieksup the load ofthe. engine,- andgresnient cushioning meansreactingbe'tween theact at'o'r and-#collar Ito yieldingly resist' "saidthrust., o .fthe actuator duringjoperation of thejst r, sa..cushibiriinameans 'beine disnosedidn .argunbroken cirttmferentiaiportieri nf theA actuator, "anni wholly to onelside of hthe colla 4 3.In Van :engine 'starterof-the 'tyiiefhavngfa pinion propelled 4'along ra` 'power sl'iaft ,Y frito and out of "mesh WitnQaneUgine'gearby'rja'ti-vr'ota, tionbetween screwtl'ireadedjpats, lll efliriion andanvactuator forthejpinionslldablyf mounted. 0n -the l power*l Shaft, aldlYDgCOnnebll'fn .Iiweem the, powerY 'shaft and 'aolillforjconipsle'evej'on `the, actuatorjeXte dingg'aXi 4 yfrom "in "afdirec'tion awayfrornftheip; ion circumferentially spaced drive V'n'glrs on fthev offsaid Isleeve remote ffro'm the pi jon; ."c

sleeve to provide afsplined `driving`connection 'between the power shaftand the actuator; an annular skirt projecting axially from saidabutments with its free end facing the actuator and telescoped over thedrive fingers to cover at least the inner ends of the same andcushioning means on the sleeve reacting between said end of the skirtand apart on the actuator for yieldingly resisting axial motion of theactuator away from the pinion toward the abutments.

4. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between screw threadedV parts on the pinion and an actuator forthe pinion slidably mounted on the power shaft, a driving connectionbetween the power shaft and actuator comprising: a sleeve on theactuator extending axially therefrom in a direction away from thepinion; circumferentially spaced drive fingers on the end of said sleeveremote from the pinion; circumferentially spaced fixed abutments on thepower shaft engaged between said drive ngers -on the sleeve to provide asplined driving connection between the power shaft and the actuator; anannular skirt projecting axially from said abutments with its free endfacing the actuator and telescoped over the drive fingers to cover atleast the inner ends of the same; cushioning means on the sleevereacting between said end of the skirt and a part on the actuator foryieldingly resisting axial motion of the actuator away from the piniontoward the abutments; and interengaging parts on the sleeve and saidabutments for limiting axial motion of the actuator away from saidabutments.

5. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between screw threaded parts on the pinion and an actuator forthe pinion slidably mounted on the power shaft, a driving connectionbetween the power shaft and actuator comprising: a collar xed on thepower shaft remote from the pinion, said collar having a longitudinalgroove cut in its bore and extending to the opposite ends of the collar;a sleeve on the actuator extending axially therefrom toward the collar;a drive nger on the extremity of the sleeve remote from the pinionreceived within said longitudinal groove of the collar to provide asplined driving connection between the collar and actuator, the drivefinger extending entirely through said groove with its outer extremitydisposed exteriorly of the end of the collar opposite the actuator; alug on said extremity of said drive finger struck therefrom over saidend of the collar remote from the pinion to limit axial movement of theactuator away from the collar; and resilient cushioning means reactingbetween the actuator and the collar and encircling said sleeve inwardlyof the drive finger for yieldingly resisting axial thrust of theactuator toward the collar during operation of the starter.

6. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between the pinion and power shaft: an actuator for the pinionslidably mounted on the power shaft and having external screw threadsthereon cooperating with an internally screw threaded part on the pinionso that rotation of the actuator relative to the pinion effects axialmotion of the pinion along the power shaft; a sleeve on the actuatorencircling the power shaft and extending axially therealong away fromthe 6 pinion, said sleeve having circumferentially spaced longitudinalslots in its extremity remote from the pinion; a collar received on saidsleeve and substantially enclosing the slots thereof; circumferentiallyspaced driving abutments in the bore of the collar received in saidslots of the sleeve to provide a substantially enclosed splined drivingconnection between the collar and actuator; means rigidly anchoring saidcollar onto the power shaft so that rotation of the shaft is translatedinto rotation of the actuator; and cushioning means received on saidsleeve at the pinion side of the collar and reacting between theactuator and collar to yieldingly resist axial thrust of the actuatortoward the collar during operation of the starter.

v'7. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between screw threaded parts on the pinion and an actuator forthe pinion slidably mounted on the power shaft, a driving co-nnectionbetween the power shaft and actuator comprising: a sleeve on theactuator encircling the power shaft and extending axially therealongaway from the pinion, said sleeve having a longitudinal slot in itsextremity remote from the actuator; a collar received on said sleeve; adriving abutment extending substantially radially into the bore of thecollar and entering the slot in the sleeve so as to provide a splineddriving connection between the collar and actuator; means anchoring thecollar to the power shaft so that the actuator rotates therewith; asplit spring ring encircling the sleeve at the side of the collar remotefrom the pinion and sprung into notches in the sleeve so as to form astop thereon engaged by the collar to limit axial motion of the actuatoraway from the collar; and cushioning means received on said sleeve andreacting between the collar and an abutment on the actuator toyieldingly hold the actuator and collar axially separated and foryieldingly resisting thrust of the actuator toward the collar developedduring operation of the starter.

8. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between the pinion and power shaft: an actuator for the pinionslidably mounted on the power shaft and including an externally screwthreaded forward portion and an unthreaded sleeve extending axiallyrearwardly from the threaded portion of the actuator, the screw threadson said forward portion terminating in abrupt shoulders at the junctionbetween the sleeve and forward threaded portion of the actuator; asleeve on the pinion having internal screw threads for cooperation withthe screw threaded portion of the actuator so that rotation of theactuator relative to the pinion effects axial motion of the pinion alongthe power shaft, said actuator sleeve having circumferentially spacedlongitudinal slots in its extremity remote from the pinion providingdrive fingers; a collar received on the actuator sleeve at the slottedend portion thereof; circumferentially spaced driving abutments in thebore of the collar received in said slots of the actuator sleeve so asto cooperatewith said drive fingers in the provision of a splineddriving connection between the collar and actuator; means securing saidcollar to the power shaft so that rotation of the shaft is translatedinto rotation of the actuator; and cushioning means received on saidactuator sleeve between the abutments formed by the ends of thevactuator threads and said collar and reacting: therebetween toyieldingly resist aXiai thrust off the actuator toward the .collarduring operation .ofthe starter, said pinion sleeve having an axiallength such as to permit engagement thereofwith said cushioning. meansupon relative rotation: between the; actuator and pinion in a directionto retract the pinion to an inoperative position -with respect to theengine gear whereby the nusliioning means absorbs the shock of pinionretraction.

:95.1 In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear bv relativerotation between the pinion and power shaft: a substantially tubularactuator for the pinion having external screw threads on its forwardportion wit-l1 the root diameter of. said threads substantially egual to4the diameter of the unthreaded rear portion ofthe actuator; a sleeve onthe pinion having internal screw threads for cooperation with 'th-ethreads on the actuator so that Vrotation of :the .actuator relative ,tothe pinion enects axial motion of trie pinion along the power shaft; acollar fared on the power lshaft and having cir.- cumerentially spacedlongitudinal grooves in its bor-cito provide driving abutmentstherebetween; drive :fingers on the iin-threaded rear portion oftheactnator and received within said grooves in the bore of 'the col-larfor cooperation with the ents thereon in the provisionof a ed drang`cannection between the actuator anoxcolglar :permitting a degree ofaxialmovement of actuator toward the coll-ar in response to enel thrustdeveloped as the sta-rter pic-ks up the load of the engine; andresilient cushioning nmeans received on the unth-readed rear portion ofthe actuator fin a posi-,tion to be engaged bythe pinion sleeve `d ringaxial Amotion of the pinion toward the collar .cto itsV inoperativeretracted `posit-ion for absorbing the shock `of pinion retraction, saidcushioning means reacti-ngbetween the actuator and' collar to`yieldingly resist said thrust of the actuator during operation of Athestarter.

10. In an engine starter of the type having a pinion propelled along apower shaft into and out of mesh with an engine gear by relativerotation between screw threaded parts on the pinion and an actuator forthe pinion slidably mounted on the power shaft, a driving connectionbetween the power-shaft and actuator, comprising: circumfer entiall-yspaced abutments on the power shaft re.- rnote from the pinion; a sleeveon the actuator extending outwardly from one end thereof toward saidshaft abutments; -circumferentially spaced 8 abutments on said; sleeveengaged with the shaft abutments to prov-ide a splined,drivingconneetion between the shaft. and actuator allow-ingY a degreeof axial motion of the actuator along the shaft; a stop `on the actuatorlocated between the pinion and said shaft abutments; means'l on theshaft providing aistop so located along the shaft as to lie lbetween theactuatorv stop and said actua.- tor and shaft abutments and resi-lientcushioning. means encircling the actuator inwardly of' saidsplineddrivng connection and` confined between saidactuator andl shaftstops' for yie-ldingly resiste ingaxial motion of the actuator towardthe shaft ehutments. Y

lll- In ,engine starter .of the type havingia pinion propelled along apower shaft into and out or mesh with an engi-ne: gear by relativerotation betweenscrew threaded parts on the pinion and an actuator for.the pin-.ion slidablv mounted .on the power shaft, aidriving,connection between the tower ,shaft and actuator, comprising:circumferential-ly -spasmi abutments on the power shaft remote from: thepinion; a sleeveon the actuator extend-ing outwardly from .one endthereof towardsaiel shaft labutnients; ,ci-rcumferentially spacedchatrooms ce :Saidsleeve engaged with the shaft abtrtifnents to prov-ideasplined driving connection between the simo-ft and actua-tor allowing adegree of axial motion `ot Ythe actuator along theV shaft; s Y n theactuatorlocated between lthe pinion andasse @l actuator abutments: meansonthesbaft il relies-.seid shaft aridvsleeve ab-utments to Sub.-

gv enclose .the semasad means having@ part trending a Sion so latedalone the Shaft as to be positioned between the acgllatonstop and saidsleeve and shaft fabu'trnents; vand `resilient cushioning means,encircling the actuator inwardly of vsaid splined driving connectionand coz fined between-said actuator and shattstops for yieldinglyresisting axial motion .of the .actuator toward the .shaft abutments.

GLENN. Ys. 'reco/tesori.

REEERENCES GITE!) lThe following references are lof record in the fil-.eo f. ;tliis patent:

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